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path: root/security/integrity/ima/ima_modsig.c
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2023-10-20ima: Add __counted_by for struct modsig and use struct_size()Gustavo A. R. Silva
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). Also, relocate `hdr->raw_pkcs7_len = sig_len;` so that the __counted_by annotation has effect, and flex-array member `raw_pkcs7` can be properly bounds-checked at run-time. While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member. This code was found with the help of Coccinelle, and audited and fixed manually. Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/ZSRaDcJNARUUWUwS@work Signed-off-by: Kees Cook <keescook@chromium.org>
2023-06-06ima: Fix build warningsRoberto Sassu
Fix build warnings (function parameters description) for ima_collect_modsig(), ima_match_policy() and ima_parse_add_rule(). Fixes: 15588227e086 ("ima: Collect modsig") # v5.4+ Fixes: 2fe5d6def167 ("ima: integrity appraisal extension") # v5.14+ Fixes: 4af4662fa4a9 ("integrity: IMA policy") # v3.2+ Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Move comprehensive rule validation checks out of the token parserTyler Hicks
Use ima_validate_rule(), at the end of the token parsing stage, to verify combinations of actions, hooks, and flags. This is useful to increase readability by consolidating such checks into a single function and also because rule conditionals can be specified in arbitrary order making it difficult to do comprehensive rule validation until the entire rule has been parsed. This allows for the check that ties together the "keyrings" conditional with the KEY_CHECK function hook to be moved into the final rule validation. The modsig check no longer needs to compiled conditionally because the token parser will ensure that modsig support is enabled before accepting "imasig|modsig" appraise type values. The final rule validation will ensure that appraise_type and appraise_flag options are only present in appraise rules. Finally, this allows for the check that ties together the "pcr" conditional with the measure action to be moved into the final rule validation. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-28ima: Fix use after free in ima_read_modsig()Thiago Jung Bauermann
If we can't parse the PKCS7 in the appended modsig, we will free the modsig structure and then access one of its members to determine the error value. Fixes: 39b07096364a ("ima: Implement support for module-style appended signatures") Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Julia Lawall <julia.lawall@lip6.fr> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05ima: Define ima-modsig templateThiago Jung Bauermann
Define new "d-modsig" template field which holds the digest that is expected to match the one contained in the modsig, and also new "modsig" template field which holds the appended file signature. Add a new "ima-modsig" defined template descriptor with the new fields as well as the ones from the "ima-sig" descriptor. Change ima_store_measurement() to accept a struct modsig * argument so that it can be passed along to the templates via struct ima_event_data. Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05ima: Collect modsigThiago Jung Bauermann
Obtain the modsig and calculate its corresponding hash in ima_collect_measurement(). Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05ima: Implement support for module-style appended signaturesThiago Jung Bauermann
Implement the appraise_type=imasig|modsig option, allowing IMA to read and verify modsig signatures. In case a file has both an xattr signature and an appended modsig, IMA will only use the appended signature if the key used by the xattr signature isn't present in the IMA or platform keyring. Because modsig verification needs to convert from an integrity keyring id to the keyring itself, add an integrity_keyring_from_id() function in digsig.c so that integrity_modsig_verify() can use it. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05ima: Add modsig appraise_type option for module-style appended signaturesThiago Jung Bauermann
Introduce the modsig keyword to the IMA policy syntax to specify that a given hook should expect the file to have the IMA signature appended to it. Here is how it can be used in a rule: appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig With this rule, IMA will accept either a signature stored in the extended attribute or an appended signature. For now, the rule above will behave exactly the same as if appraise_type=imasig was specified. The actual modsig implementation will be introduced separately. Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>